Work stop



Nov. 22, 1949 v c. o. MCDONALD 2,488,822

WORK STOP Filed Jan. 13, 19 7 Fig. 2.

g/ 3 I0 -F E F Fig.5. 4 I Invent 0r 4 Carl 0. McDonald Patented Nov. 22, 1949 UNITED STATES PATENT OFFICE WORK STOP Carl 0. McDonald, Osborn Vle', Ohio Application January 13, 1947, Serial No. 721,834 3 Claims. (Cl. 279-123) This invention relates to an improved work stop expressly constructed and designed for adaptable use in connection with a lathe chuck and has reference, more particularly, to a stop of micrometer-form which is not only an effective stop or check but is, in addition, a work positioning and position establishing gage.

An object of the invention is to provide a simple and highly practical combination work stop and gage which lends itself aptly and suitably applicable to a regularly constructed lathe chuck jaw and which is precision made and so mounted that it serves to accommodate a relatively thin workpiece for reliable turning, tooling and facing results.

Another object of the invention is to provide a readily attachable jaw-type work stop, the work end of which may be caused to retract and wholly recede into an adapter socket which is provided therefor in the companion and complemental jaw, whereby to permit said end to be projected for use, when wanted, and retracted to an out-ofthe-Way position when not readied for use.

A further object of the invention has to do with work stops, one for each chuck jaw, this in order that the respective stops may be relatively adjusted with requisite niceties in order to make way for proper handling, and turning a taper on a facing cut.

From a purely structural aspect, the preferred embodiment of the invention takes the form of a double-threaded and shouldered stud, the inner end being threaded for anchorage on the coacting jaw and the outer end carrying a cylindrical cap or thimble and the latter being provided with oiling, adjusting and calibrated locating facilities.

Other objects, features and advantages will become more readily apparent from the accompanying sheet of drawings.

In the drawings, wherein like numerals are utilized to designate like parts throughout the views:

Figure 1 is an elevational view of a lathe chuck showing the work-piece held in the Jaws, and the work stops interposed between the work-piece and jaws.

Figure 2 is likewise an elevational view based on Figure 1 but showing the stops set for turning a taper on a facing cut, this being one of the advantages of the improved stops.

Figure 3 is a detailed perspective view of a cylindrical screw-cap, this being the adjustable part of the improved work stop.

Figure 4 is a fragmentary sectional view of one of the chuck Jaws, on an enlarged scale, and showing the work stop partly in elevation and partly in section and projected for use.

Figure 5 is a face or elevational view of Figure 4 observing the same in a direction from right to left.

In Figures 1 and 2 the lathe chuck, which is conventional, is denoted by the reference character A, the same being provided on its working side or face with jaws B, all the same in construction. As shown, particularly in Figures 4 and 5, the side of the jaw which is adapted to receive and clamp the work C in place is of stepped formation as indicated generally at D. The work clamping portion is denoted at E and the complemental steps at F and G.

In carrying out the principles of this invention the step or surface F is formed with a bore 1- having a screw-threaded counter bore 8 at its inner end. The work stop unit comprises a stud having a screw-threaded portion 9 which is screwed into the counter bore 8 and a screwthreaded shank portion lfl, together with a stopshoulder II. The shoulder H is in the form of a hexagonal nut and abuts the inner end of the main bore or socket i. The shank I0 is of a length less than the depth of the socket I, and serves to accommodate the cylindrical screw-cap l2. The screw-cap is of a length to permit the same to be screwed into and housed completely within the limits of the socket l, as is obvious.

the center is a conveniently accessible and usable oiling hole. There are additional peripheral graduations at l6 cooperating with the graduations H in an obvious easy-to- The numerals I1 designate addias is employed and handily used to facilitate turning and adjusting the cap.

Referring again to Figures 1 and 2 it is obvious that these views are the same except that Figure 2 advantages of the It is also to be mentioned detachable and are precision made to attain the ends desired. Then, erable at right angles to the longitudinal axis of too. each stop-is such that the work end of the said jaw and including a screw-threaded stud cap may be caused to retract and wholly recede with a screw-cap mounted on said stud, the visiinto the adaptor socket I, this to permit said ble outer end portion of said cap having a scale end to be projected for use as shown in Figure 5 with graduations providing a dial, and the adja- 4, when wanted, or screwed in and retracted to cent rim portion of the cap being provided with an out-of-the-way position when not in use. In additional scale forming graduaticns. this "out-of-the-way" position the work end of 3. As a new article of manufacture and as a the cap is substantially flush with the surface F. component part of a structural assemblage of A careful consideration of the foregoing dethe class described, a work stop adapted to be scription in conjunction with the invention as adjustably and detachably mounted on the inillustrated in the drawings will enable the reader termediate portion of a conventional-type work to obtain a clear understanding and impression clamping and retaining jaw, said work stop comof the alleged features of merit and novelty sufiiprising a stud having at its inner end coarse atcient to clarify the construction of the invention taching and anchoring threads and fine adjustas hereinafter claimed. ment threads at its outer end, an internally Minor changes in shape, size, materials and screw-threaded cap screwed on the threads at rearrangement of parts may be resorted to in the outer end of the stud, the outer end of said actual practice so long as no departure is made cap being provided with scale graduations said from the invention as claimed. stud being provided at the juncture of the coarse What is claimed as new is: and fine threads with a laterally outstanding stop 1. In 8 S ruc e f the 5 described. in flange, the outer marginal edge portions of said combination, a lathe chuck, a plurality of conflange being flat-faced to provide convenient tool ventional-type work clamping and retaining jaws grip.

mounted for operation on the work face of said CARL O. McDONALD. chuck, and a work stop separably mounted on and carried entirely by each jaw, said stop be- REFERENCES CITED mg a precision mmmmeter'type unit and being The following references are of record in the operable at right angles to the longitudinal axis i this ten 2 of said jaw and including a screw-threaded stud me 0 pa b with a screw-cap mounted on said stud. UNITED STA'I'ES PATENTS 2. In a structure of the class described, in Number Name Date com ina ion. a lathe chuck, a plurality of con- 177,031 Tierney May 2 1876 ventional-ty-pe work clamping and retaining jaws, 199,734 Bmmbaugh Jan 29 1878 mounted for operation on the work face or said 609 019 Gibbs Aug. 1898 chuck, nd a work s op separably mounted on 13721726 Sloan Man 29, 1921 and carried entirely by each jaw, said stop-being a precision micrometer-type unit and being op- 

